Interrail is a ticket which can be used to travel in Europe by train 

Regions

A    England, Ireland
B    Sweden, Norway, Finland
C    Denmark, Germany, Austria, Switzerland
D    Poland, Czech Republic, Slovakia, Hungary, Croatia,
      Bosnia-Herzogovinia
E    France, Belgium, Netherlands, Luxemburg
F    Spain, Portugal, Morocco
G    Italy, Slovenia, Greece, Turkey
H    Bulgaria, Romania, Yugoslavia, Macedonia

You can choose one of the following

1 region  - 12 days
1 region  - 22 days
2 regions - 30 days
3 regions - 30 days
Global (all regions) - 30 days

More Information
 
www.interrailnet.com